Substituted caprolactam derivatives as antihypertensives

ABSTRACT

The invention in its broad aspects relates to caprolactam derivatives which are useful as angiotensin converting enxyme inhibitors and as antihypertensives.

This is a continuation-in-part application of application Ser. No.282,580 filed July 13, 1981, now abandoned, which, in turn, is acontinuation-in-part of application Ser. No. 179,305 filed Aug. 18,1980, now abandoned.

BACKGROUND OF THE INVENTION

The invention in its broad aspects relates to caprolactam derivativeswhich are useful as angiotensin converting enzyme inhibitors and asantihypertensives. The compounds of this invention can be shown by thefollowing formula: ##STR1## wherein R and R⁴ are the same or differentand are hydroxy,

lower alkoxy,

lower alkenoxy,

aryloxy (such as phenoxy),

dilower alkylamino lower alkoxy (e.g., dimethylaminoethoxy),

acylamino lower alkoxy (e.g., acetylaminoethoxy, nicotinoylaminoethoxy,succinimidoethoxy),

acyloxy lower alkoxy (e.g., pivaloyloxyethoxy),

arloweralkoxy (such as benzyloxy, p-methyoxybenzyloxy),

hydroxy or dihydroxyloweralkoxy (such as glyceryloxy),

amino,

hydroxyamino;

R¹ is hydrogen,

alkyl of from 1 to 12 carbon atoms which include straight and branchedalkyl groups;

alkenyl of from 2-12 carbon atoms which include straight and branchedalkenyl groups;

alkynyl of from 2-12 carbon atoms which include straight and branchedalkynyl groups;

cycloalkyl of from 3 to 10 carbon atoms;

substituted loweralkyl wherein the substituent(s) can be halo, loweralkoxy, aryloxy (such as phenoxy), amino, lower alkylamino,aminoloweralkylthio, hydroxy, aminoloweralkoxy, diloweralkylamino,acylamino, (such as acetamido and benzamido), arylamino, (such asphenylamino), guanidino, phthalimido, mercapto, loweralkylthio, arylthio(such as phenylthio), carboxy, carboxamido or carboloweralkoxy,

arloweralkyl, arloweralkenyl, heteroarlower alkyl or heteroarloweralkenyl (such as benzyl, styryl, indolylethyl, imidazolylmethyl,naphthylethyl),

substituted arloweralkyl, or substituted heteroarlower alkyl wherein thearyl or heteroaryl substituent(s) is halo, dihalo, lower alkyl, hydroxy,lower alkoxy, amino, aminomethyl, phenyloxy, acylamino,diloweralkylamino, loweralkylamino, carboxyl, haloloweralkyl, acyl oraroyl; and the alkyl portion may be substituted by amino, hydroxyl oracylamino;

R² is hydrogen, lower alkyl, cyclic lower alkyl, amino lower alkyl,alkylaminoloweralkyl, hydroxyalkyl, acylaminoloweralkyl, dialkylaminolower alkyl including cyclic polyethyleneamino lower alkyl, arloweralkyl, aryl, substituted aryl wherein the substituent is halo, alkyl,aminoalkyl, or alkoxy, heteroaryl heteroarlower alkyl;

R³ is hydrogen, lower alkyl, phenyl, phenyl lower alkyl, hydroxyphenyllower alkyl, hydroxy lower alkyl, amino lower alkyl, acylamino loweralkyl, guanidino lower alkyl, imidazolyl lower alkyl, indolyl loweralkyl, mercapto lower alkyl or lower alkyl thio lower alkyl;

R⁵ is hydrogen or lower alkyl;

and, the pharmaceutically acceptable salts thereof.

As used throughout this application, including the claims, and unlessspecified otherwise:

alkyl denotes straight and branched hydrocarbons of C₁ -C₁₂ andloweralkyl denotes straight and branched hydrocarbons of C₁ -C₈ ;alkenyl denotes straight and branched hydrocarbons of C₂ -C₁₂ andloweralkenyl denotes straight and branched hydrocarbons of C₂ -C₈, eachof which contains a double bond; alkynyl denotes straight and branchedhydrocarbons of C₂ -C₁₂ and loweralkenyl denotes straight and branchedhydrocarbons of C₂ -C₈, each of which contains a triple bond; aryl andthe prefix "ar" denote unsubstituted aromatic ring or rings of C₆ -C₁₂such as, for example, phenyl, naphthyl, biphenyl; acyl denotes acarboxylic acid derivative represented by the formula ##STR2## wherein Ris alkane, aralkane, arene, heteroarene, heteroaralkene, and substitutedderivatives thereof so that aryl denotes, for example, alkanoyl, aroyl,aralkanoyl, heteroaryl, heteroaralkanoyl, and the like; cycloalkyldenotes an unsubstituted alkyl ring of C₃ -C₁₀ ; hetero denotes theheteroatoms N, O or S; heteroaryl denotes an aryl group containing aheteroatom; heteroacycle denotes a saturated or unsaturated aromatic ornon-aromatic cyclic compound containing a heteroatom; halogen or halodenote F, Br, Cl or I atoms; loweralkoxy denotes an alkyl group with O;

Exemplary loweralkyl or lower alkenyl groups include, for example,methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl,isopentyl, hexyl or vinyl, allyl, butenyl and the like, and exemplaryheteroaryl groups include, for example, pyridyl, thienyl, furyl,indolyl, benzthienyl, imidazoyl, thiazolyl and quinolinyl.

Preferred are those compounds of Formula I wherein:

R and R⁴ are the same or different and are hydroxy, lower alkoxy, andarloweralkoxy;

R² is hydrogen, loweralkyl, aminoloweralkyl, aralkyl, aryl, heteroaryl,or heteroaralkyl;

R⁵ is hydrogen;

R¹ is alkyl having from 1 to 8 carbon atoms, substituted lower alkylwherein the alkyl group has 1-5 carbon atoms and the substituent isamino, acylamino, hydroxy, aminoloweralkylthio, aminoloweralkoxy,arylthio, aryloxy or arylamino, aralkyl or heteroaralkyl wherein thealkyl portion has 1 to 3 carbon atoms (such as phenethyl orindolylethyl) or substituted arloweralkyl (phenyl lower alkyl ornaphthyl lower alkyl) and substituted heteroarloweralkyl wherein thealkyl groups have 1-3 carbons optionally substituted with amino, hydroxyor acylamino and wherein the substituent(s) on the aryl or heteroarylgroups is halo, dihalo, amino, aminoalkyl, hydroxy, lower alkoxy, loweralkyl, phenoxy or benzoyl;

R³ is hydrogen, lower alkyl, phenyl lower alkyl, hydroxy phenyl loweralkyl, amino lower alkyl, imidazolyl lower alkyl, indolyl lower alkyl,lower alkyl thio loweralkyl.

More preferred are compounds of Formula I wherein

R³ is hydrogen, lower alkyl, amino lower alkyl, indolyl lower alkyl,phenyl lower alkyl;

R¹ is alkyl from 1 to 8 carbon atoms; substituted lower alkyl whereinthe alkyl group has 1-5 carbon atoms and the substituent is amino,acylamino, hydroxy, aminoloweralkylthio, arylthio, aryloxy; aralkyl orheteroaralkyl wherein the alkyl portion has 1-3 carbon atoms (such asphenethyl or indolylethyl) or substituted arloweralkyl and substitutedheteroarloweralkyl wherein the alkyl groups have 1-3 carbons optionallysubstituted with amino, acylamino or hydroxy and wherein thesubstituent(s) on the aryl and the heteroaryl groups is halo, ammino,aminoalkylhydroxy, or lower alkoxy;

R⁵ is hydrogen;

R² is hydrogen, lower alkyl, aminoloweralkyl, aryl, or aralkyl;

R and R⁴ are independently hydroxy, lower alkoxy, or arloweralkoxy.

Most preferred are compounds of Formula I wherein

R³ is hydrogen or lower alkyl;

R¹ is alkyl of 1-8 carbons; substituted lower alkyl wherein the alkylgroup has 1-5 carbon atoms and the substituent is amino, acylamino,arylthio, aryloxy; aralkyl or heteroaralkyl wherein the alkyl portionhas 1-3 carbon atoms (such as phenethyl or indolyethyl); or substitutedaralkyl or substituted heteroarloweralkyl wherein the alkyl groups have1-3 carbons and the substituents on the aryl or heteroaryl groups arehalo, amino, aminoalkyl, hydroxy, or loweralkoxy;

R⁵ is hydrogen;

R² is hydrogen, lower alkyl, aminoloweralkyl or aryl;

R and R⁴ are independently hydroxy, lower alkoxy or benzyloxy.

The preferred, more preferred and most preferred compounds also includethe pharmaceutically acceptable salts thereof.

The products of Formula (I) and the preferred subgroups can be producedby one or more of the methods and subroutes depicted in the followingequations. The definitions of R, R¹, R², R³, R⁴, and R⁵ are the same asin Formula (I) except where noted. ##STR3## R⁷ =OH, OR⁹ R⁹ =lower alkyl,aryl or aralkyl

R⁸ =benzyloxycarbonyl, t-butoxycarbonyl, other appropriate blockinggroups known in peptide chemistry.

X=iodo or bromo

Lysine [or an (ε-substituted lysine (R² ≠H) which can be prepared by theprocedure of Blicke et al., J. Am. Chem. Soc, 76, 2317 (1954) followedby that of Tull et al., J. Org. Chem. 29, 2425 (1964)] is converted tothe N.sup.α -protected derivative II by methods known in the art.Suitable protecting groups R⁸ include the phthalimido, t-butoxycarbonyl,and benzyloxycarbonyl groups. R⁷ may be OH or alkoxy as the methodsbelow require and R⁴ is as defined. Intermediate II is reductivelycoupled with the keto acid or ester III in aqueous solution, preferablynear neutrality or in a suitable organic solvent, such as methanol oracetonitrile, in the presence of sodium cyanoborohydride or ifprotecting groups do not interefere with hydrogen and a suitablecatalyst to yield IV. This intermediate, with R⁴ =OH and R⁷ =OR⁹, iswarmed in an organic solvent, such as acetonitrile, with a base such astriethylamine to obtain the perhydroazepinone V. The blocking group R⁸is removed by appropriate known methods, and the resulting compound VIis reductively coupled with keto acid, ester, etc. VII to obtain I.Substituents at R and R⁴ may be altered by standard methods if desired.

Intermediate II may also be alkylated with a haloester such as VIII.

Furthermore, intermediate IV with R⁴ not OH and R⁷ =OH may be cyclizedto V by the use of dicyclohexylcarbodiimide and N-hydroxysuccinimide ina suitable solvent such as DMF or methylene chloride. Other knownpeptide coupling methods may also be used if desired. ##STR4##

Alternatively a hydroxyaminoacid X [Gandry, Can. J. Res., 26B, 387(1948)] is converted to the N-protect hydroxy acid XI by establishedtechniques, then the terminal hydroxyl is activated by known methodssuch as conversion to the tosyl ester XII or to the bromide XIII.Reaction with amino acid XIV affords the intermediate IV, which may beconverted to I as described above. ##STR5##

Substituted caprolactams (R² ≠H), are conveniently prepared via Beckmanring expansion of the corresponding 2-substituted cyclohexanone oximesusing standard reaction conditions. These caprolactams can then behalogenated and converted to 3-amino derivatives via displacementreactions described, for example, by Blacket, et al. and Tull, et al.above; Wineman, et al., J. Am. Chem. Soc. 80, 6233 (1958) and Francis etal., J. Am. Chem. Soc. 80, 6238 (1958). Aminolactams XV are thenalkylated on the exocyclic nitrogen using reagents VII or IX by themethods described above to obtain XVI. Alkylation of XVI with VIII inthe presence of a strong base such as sodium hydride in a solvent suchas DMF or THF affords I. ##STR6##

The halocaprolactam XVII (Blicke and Tull cited above) can also bealkylated with reagent VIII in the presence of a strong base such assodium hydride in a suitable solvent such as DMF or THF to obtain thealkylated halolactam XVIII. Treatment with azide ion followed bycatalytic hydrogenation affords the intermediate VI described above.##STR7##

The halocaprolactam XVII is reacted with the amino acid derivative XIXto obtain the intermediate XVI for conversion to I as described above.

The starting materials which are required for the above processes hereindescribed are known in the literature or can be made by known methodsfrom known starting materials.

In products of general Formula (I), the carbon atoms to which, R¹, R²and R³ are attached and the ring carbon atom to which the fragment##STR8## is attached may be asymmetric. The compounds accordingly existin diastereoisomeric forms or as enantiomers or mixtures thereof. Theabove described syntheses can utilize racemates, enantiomers ordiastereomers as starting materials and intermediates. Whendiastereomeric products result from the synthetic procedures, thediastereomeric products can be separated by chromatographic orfractional crystallization methods. When racemic products result, theymay be resolved by crystallization of salts of optically active acids orbases or by other methods known in the art. The asymmetric carbon atomsspecified above may be in two configurations (S or R) and both arewithin the scope of this invention, although S is generally preferredexcept for the configurations at the carbon to which R² is attached asexemplified in specific compounds of this invention.

The compounds of this invention form salts with various inorganic andorganic acids and bases which are also within the scope of theinvention. Such salts include ammonium salts, alkali metal salts likesodium and potassium salts, alkaline earth metal salts like the calciumand magnesium salts, salts with organic bases, e.g., dicyclohexylamine,N-methyl-D-glucamine, salts with amino acids like arginine, lysine andthe like. Also salts with organic and inorganic acids may be prepared;e.g., HCl, HBr, H₂ SO₄, H₃ PO₄, methanesulfonic, toluenesulfonic,maleic, fumaric, camphorsulfonic acids. The non-toxic physiologicallyaceptable salts are particularly valuable, although other salts are alsouseful, e.g., in isolating or purifying products.

The salts may be formed by conventional means, as by reacting the freeacid or free base forms of the product with one or more equivalents ofthe appropriate base or acid in a solvent or medium in which the salt isinsoluble, or in a solvent such as water which is then removed in vacuoor by freeze-drying or by exchanging the cations of an existing salt foranother cation on a suitable ion exchange resin.

The compounds of this invention inhibit angiotensin converting enzymeand thus block conversion of the decapeptide angiotensin I toangiotensin II. Angiotensin II is a potent pressor substance. Thusblood-pressure lowering results from inhibition of its biosynthesisespecially in animals and humans whose hypertension is angiotensin IIrelated. Furthermore, converting enzyme degrades the vasodepressorsubstance, bradykinin. Therefore, inhibitors of angiotensin convertingenzyme may lower blood pressure also by potentiation of bradykinin.Although the relative importance of these and other possible mechanismsremains to be established, inhibitors of angiotensin converting enzymeare effective antihypertensive agents in a variety of animal models andare useful clinically, for example, in many human patients withrenovascular, malignant and essential hypertension., See, for example.D. W. Cushman et al., Biochemistry 16, 5484 (1977).

The evaluation of converting enzyme inhibitors is guided by in vitroenzyme inhibition assays. For example, a useful method is that of Y.Piquilloud, A. Reinharz and M. Roth, Biochem. Biophys. Acta, 206, 136,(1970) in which the hydrolysis ofcarbobenzyloxyphenylalanylhistidinylleucine is measured. In vivoevaluations may be made, for example, in normotensive rats challengedwith angiotensin I by the technique of J. R. Weeks and J. A. Jones,Proc. Soc. Exp. Biol. Med., 104, 646 (1960) or in a high renin rat modelsuch as that of S. Koletsky et al., Proc. Soc. Exp. Biol. Med., 125, 96(1967).

Thus, the compounds of the invention are useful in treatinghypertension. They are also of value in the management of adute andchronic congestive heart failure, in the treatment of secondaryhyperaldosteronism, scleroderma, primary and secondary pulmonaryhyertension, renal failure and renal vascular hypertension, and in themanagement of vascular disorders such as migraine. The application ofthe compounds of this invention for these and similar disorders will-beapparent to those skilled in the art.

In the management of hypertension and those clinical conditions notedabove, the compounds of this invention may be utilized in compositionssuch as tablets, capsules or elixirs for oral administration,suppositories for rectal administration, sterile solutions orsuspensions for parenteral or intramuscular administration, and thelike. The compounds of this invention cah be administered to patients inneed of such treatment in dosages that will provide optimalpharmaceutical efficacy. Although the dose will vary from patient topatient depending upon the nature and severity of disease, the patient'sweight, special diets then being followed by a patient, concurrentmedication, and other factors which those skilled in the art willrecognize, the dosage range will generally be about 1 to 200 mg perpatient per day which can be administered in single or multiple doses.Preferably, the dosage range will be about 2.5 to 100 mg per patient perday.

It is often advantageous to administer compounds of this invention incombination with other antihypertensives and/or diuretics. For example,the compounds of this invention can be given in combination with suchcompounds as amiloride, atenolol, bendroflumethiazide, chlorothalidone,chlorothiazide, clonidine, cryptenamine acetates and cryptenaminetannates, deserpidine, diazoxide, guanethidene sulfate, hydralazinehydrochloride, hydrochlorothiazide, hydroflumethiazide, metolazone,metoprololtartate, methyclothiazide, methyldopa, methyldopatehydrochloride, minoxidil,(S)-1-{[2-(3,4-dimethoxyphenyl)ethyl]amino}-3-{[4-(2-thienyl)-1H-imidazol-2-yl]phenoxy}-2-propanol,polythiazide, the pivaloyloxyethyl ester of methyldopa, indacrinone andvariable ratios of its enantiomers, rifedipine, verapamil, diltiazam,flumethiazide, bendroflumethiazide, atenolol,(+)-4-[3-{[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl}propyl}benzoicacid, bumetanide, prazosin, propranolol, Rauwolfia serpentina,rescinnamine, reserpine, spironolactone, timolol, trichlormethiazide,benzthiazide, quinethazone, triamterene, acetazolamide, aminophylline,cyclothiazide, merethoxylline procaine, and the like, as well asadmixtures and combinations thereof.

Typically, the individual daily dosages for these combinations can rangefrom about one-fifth of the maximum recomended levels for the entitieswhen they are given singly.

To illustrate these combinations, one of the antihypertensives of thisinvention effective clinically in the 2.5-100 milligrams per day rangecan be effectively combined at levels at the 0.5-100 milligrams per dayrange with the following compounds at the indicated per day dose range:hydrochlorothiazide (10-100 mg), timolol (5-60 mg), methyl dopa (65-2000mg), the pivaloyloxyethyl ester of methyl dopa (30-1000 mg), indacrinoneand variable ratios of its enantiomers (25-150 mg) and(+)-4-{3-{-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl}propyl}-benzoicacid (10-100 mg).

In addition, the triple drug combinations of hydrochlorothiazide (10-100mg) plus timolol (5-60 mg) plus converting enzyme inhibitor of thisinvention (0.5-100 mg) or hydrochlorothiazide (10-100 mg) plus amiloride(5-20 mg) plus converting enzyme inhibitor of this invention (0.5-100mg) are effective combinations to control blood pressure in hypertensivepatients.

Naturally, these dose ranges can be adjusted on a unit basis asnecessary to permit divided daily dosage and, as noted above, the dosewill vary depending on the nature and severity of the disease, weight ofpatient, special diets and other factors.

Typically, these combinations can be formulated into pharmaceuticalcompositions as discussed below.

About 0.5 to 100 mg. of a compound or mixture of compounds of Formula Ior a physiologically acceptable salt is compounded with aphysiologically acceptable vehicle, carrier, excipient, binder,preservative, stabilizer, flavor, etc., in a unit dosage form as calledfor by accepted pharmaceutical practive. The amount of active substancein these compositions or preparations is such that a suitable dosage inthe range indicated is obtained.

Illustrative of the adjuvants which may be incorporated in tablets,capsules and the like are the following: a binder such as gumtragacanth, acacia, corn starch or gelatin; an excipient such asmicrocrystalline cellulose; a disintegrating agent such as corn starch,pregelatinized starch, alginic acid and the like; a lubricant such asmagnesium stearate; a sweetening agent such as sucrose, lactose orsaccharin; a flavoring agent such as peppermint, oil of wintergreen orcherry. When the dosage unit form is a capsule, it may contain inaddition to materials of the above type, a liquid carrier such as fattyoil. Various other materials may be present as coatings or to otherwisemodify the physical form of the dosage unit. For instace, tablets may becoated with shellac, sugar or both. A syrup or elixir may contain theactive compund, sucrose as a sweetening agent, methyl and propylparabens as preservarives, a dye and a flavoring such as cherry ororange flavor.

Sterile compositions for injection can be formulated according toconventional pharmaceutical practice by dissolving or suspending theactive substance in a vehicle such a water for injection, a naturallyoccurring vegetable oil like sesame oil, coconut oil, peanut oil,cottonseed oil, etc. or a synthetic fatty vehicle like ethyl oleate orthe like. Buffers, preservatives, antioxidants and the like can beincorporated as required.

The following examples are illustrative of the invention and constituteespecially preferred embodiments. The preferred diastereomers of theseexamples are isolated by column chromatography or fractionalcrystallization.

EXAMPLE 11-Carboxymethyl-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one

Dissolve 10.45 g of N.sup.α -Boc-N.sup.ε -Cbz-L-lysine in 125 mlmethanol and 17 ml water. Neutralize the solution with 27.5 ml of 0.5Mcesium carbonate solution and concentrate the resulting solution to asyrup at aspirator pressure and 35° C. Dissolve the syrup in 100 ml.dimethylformamide and concentrate; repeat once more. Dissolve theresidue in 75 ml. dimethylformamide and 2.7 ml. methyi iodide. Stir thereaction mixture overnight at room temperature then remove thedimethylformamide under vacuum (oil pump). Add 250 ml. water to theresidue and extract into 150 ml. ethyl acetate. Wash the ethyl acetateextract twice with 100 ml. portions of water then dry the organic phaseover MgSO₄. Filter and concentrate the dried solution in vacuo to obtainN.sup.α -Boc-N.sup.ε -Cbz-L-lysine methyl ester.

Prepare a solution of 11.5 g. N.sup.α -Boc-N.sup.ε -Cbz-L-lysine methylester and 3.3 g. glyoxylic acid hydrate in 80 ml. methanol. Add 2 g. 10%palladium on charcoal catalyst and hydrogenate for 3 hours at roomtemperature and an initial pressure of 40 psig. Filter the reactionmixture to remove catalyst and wash the catalyst with methanol.Concentrate the combined filtrate and washings in vacuo to N.sup.α-Boc-N.sup.ε -carboxymethyl-L-lysine methyl ester.

Add 8.0 g. N.sup.α -Boc-N.sup.ε -carboxymethyl-L-lysine methyl ester and4.7 ml. triethylamine to 2.8 L of acetonitrile and reflux the mixturefor 3 days. Cool the reaction and concentrate at aspirator pressure onthe rotary evaporator to a yellow glass. Dissolve the glass in 175 ml.CH₂ Cl₂ and wash three times with 55 ml. portions of 20% citric acid andthen twice with 55 ml. portions of 1N NaHCO₃. Combine the NaHCO₃ washesand adjust to pH 3 with 40% citric acid solution. Extract the acidifiedsolution with six 60 ml. portions of CH₂ Cl₂. Dry the organic extractover MgSO₄, filter, then concentrate at aspirator pressure to3-(S)-t-butoxycarbonylamino-1-carboxymethylperhydroazepin-2-one.

tlc (silica, 20 Ethyl acetate: 5 pyridine: 1 acetic acid: 1 water)Rf=0.8

Dissolve 2.1 g3-(S)-t-butoxycarbonylamino-1-carboxymethylperhydroazepin-2-one in 70 mlice cold 4N HCl in ethyl acetate and stir at 0° C. for 1 hour. Removethe cooling bath and bubble nitrogen through the mixture for 20 minutes.Filter the precipitate and wash with ether to obtain3-(S)-amino-1-carboxymethylperhydroazepin-2-one hydrochloride as a whitesolid. Filter the combined filtrate and washings to obtain additionalproduct.

Suspend 4.45 g 2-oxo-4-phenylbutyric acid in 25 ml water and adjust thepH to 7 with 50% NaOH. Add 1.14 g3-(S)-amino-1-carboxymethylperhydroazepin-2-one hydrochloride and againadjust the pH to 7 with 50% NaOH. Dilute the resulting solution withwater to a total volume of 60 ml then add 0.943 g sodiumcyanoborohydride. After 2 days at room temperature, add 50 ml Dowex 50(H⁺) and stir the mixture for 1 hour. Extract the mixture with ether andthen add the Dowex 50 and aqueous portion to the top of a 100 ml. columnof Dowex 50 (H⁺). Elute first with water until the eluate is neutral andthen with 2% pyridine in water until no further product elutes(ninhydrin detection). Concentrate the product containing fractions ataspirator pressure, redissolve the residue in 50 ml water and freezedry. Isolate the 1-carboxymethyl-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one as a whitehygroscopic solid.

Mass spec.: M+348; 330 (M--H₂ O); 303 (M--CO₂ H).

NMR: (D₂ O, TSS). δ1.4-2.5 (m, 8H); δ2.6-3.1 (m, 2H); δ3.3-4.0 (m, 3H);δ4.1-4.3 (m, 3H); δ7.4 (S, 5H).

EXAMPLE 21-Carboxymethyl-3-(S)-[(1-ethoxycarbonyl-3-phenylpropyl)amino]perhydroazepin-2-one

Dissolve 280 mg. 1-carboxymethyl-3-(S)-aminoperhydro-2-azepinonehydrochloride in 50 ml water and adjust the pH to 6.8 withbenzyltrimethylammonium hydroxide solution. Freeze dry the reactionmixture and dissolve the residue in 10 ml absolute ethanol. Add 1.3 gethyl 2-oxo-4-phenylbutyrate and 7.5 g powdered 4A molecular sieves. Tothis stirred mixture, add over a period of four hours 357 mg sodiumcyanoborohydride in four equal portions then stir the reaction at roomtemperature overnight. Filter the reaction and wash the filter cake withethanol. Concentrate the combined filtrate and washings in vacuo thendissolve the residue in 40 ml. water. Add 10 ml Dowex 50 (H+) and 25 mlether and stir the mixture for one hour. Remove the ether layer andextract the aqueous portion again with ether. Remove the ether and applythe aqueous slurry onto a column of 20 ml Dowex 50 (H+). Elute firstwith water until the eluate is neutral and then with 2% pyridine inwater until no further product elutes. Concentrate the productcontaining fractions in vacuo, dissolve the residue in water andlyophilize. Isolate 396 mg. of1-carboxymethyl-3-(S)-[(1-ethoxycarbonyl-3-phenylpropyl)amino]perhydroazepin-2-oneas a white powder.

NMR. (D₂ O, TSS) δ1.2-1.5 (t, 3H); δ1.5-2.6 (m, 7H); δ2.5-3.2 (m, 2H);δ3.3-3.7 (m, 3H); δ3.8-4.6 (m, 6H); δ7.4 (S, 5H),

Mass spectrum: M+ 376; 331 (M--C₂ H₅ O); 317 (M--CH₂ CO₂ H); 303 (M--CO₂C₂ H₅).

In the same manner react the3-(S)-amino-1-carboxymethylperhydroazepin-2-one with ethyl4-(3-indolyl)-2-oxobutyrate to obtain1-carboxymethyl-3-(S)-[(1-ethoxycarbonyl-3-(3-indolyl)propyl)amino]perhydroazepin-2-one.Standard alkaline hydrolysis (as in Example 3) of this material yields1-carboxymethyl-3-(s)-[(1-carboxy-3-(3-indolyl)propyl)amino]perhydroazepin-2-one.Alternatively, esterification in HCl-ethanol affords1-ethoxycarbonylmethyl-3-(S)-1-(1-ethoxycarbonyl-3-(3-indolyl)lpropyl)amino]perhydroazepin-2-one.

EXAMPLE 31-(1-Carboxyethyl)-3-(S)-[(1-carboxy-3-phenylpropyl)amino]-perhydroazepin-2-one

Dissolve 7.6 g N.sup.α -Boc-N.sup.ε -Cbz-L-lysine and 2.04 g methylpyruvate in 75 ml methanol. Add 2 g 10% palladium on charcoal andhydrogenate at an initial pressure of 40 psig for 3 hours at roomtemperature. Filter the solution and concentrate the filtrate ataspirator pressure to obtain N.sup.α -Boc-N.sup.ε-(1-methoxycarbonylethyl)-L-lysine.

Dissolve 4.76 g. of this ester and 1.64 g N-hydroxsuccinimide in 250 mldimethylformamide, cool the solution to 0° and then add a solution of3.24 g dicyclohexylcarbodiimide in 10 ml. dimethylformamide. Store thereaction mixture at 4° C. for 2 days. Remove the solvent in vacuo (oilpump) and take up the residue in chloroform. Filter the mixture and thenconcentrate the filtrate. Dissolve the residue in 1:1 ethylacetate-hexane, filter and chromatograph on silica gel using 7:3 hexane:ethyl acetate as eluent. Combine those fractions containing the desiredproduct and concentrate at aspirator pressure to afford 1.75 g.3-(S)-t-butoxycarbonyl-amino-1-(1-methoxycarbonylethyl)perhydroazepin-2-one.tlc (silica, 7:3 Hexane: Ethyl acetate) Rf 0.5 NMR (CDCl₃, TMS) δ1.2-2.4(m, 18H); δ3.2-3.6 (broad 2H); δ3.7 (S, 3H); δ4.1-4.6 (broad, 1H);δ4.5-5.4 (2q, 1H); δ 5.8-6.1 (broad, 1H). Mass spectrum: M+314 (weak);258 (M--C₄ H₈); 241 (M--C₄ H₉ O).

Dissolve 2.59 g3-(S)-t-butoxycarbonylamino-1-(1-methylcarbonylethyl)perhydroazepin-2-onein 10 ml. methanol and 10 ml water and add 0.5 ml 50% NaOH solution.Store the mixture at room temperature for 2 hours and then concentrateat aspirator pressure to a syrup. Dissolve the syrup in water and chillthe solution in an ice bath. Add 6N hydrochloric acid to pH 2 thenextract the solution several times with ethyl acetate. Dry the combinedextracts over MgSO₄, filter and concentrate the filtrate at aspiratorpressure and isolate3-(S)-t-butoxycarbonylamino-1-(1-carboxyethyl)perhydroazepin-2-one as anoil (2.04 g) which is a mixture of diastereomers. Separate the isomerson a column of XAD2 resin at 50° C. using 0.1N NH₄ OH containing 6%acetonitrile as eluent. Isolate the ammonium salt of the desired isomeras the one which elutes first (u.v. and refractive index detection).

Treat 610 mg of the desired isomer with 20 ml 4N hydrogen chloride inethyl acetate at 0° for 1 hours. Warm the mixture to room temperatureand purge with nitrogen for 20 minutes then concentrate the solution todryness. Dissolve the residue in water and reconcentrate to obtain3-(S)-amino-1-(1-carboxyethyl)perhydroazepin-2-one hydrochloride.

Dissolve 422 mg of 3-(S)-amino-1-(1-carboxyethyl)perhydroazepin-2-onehydrochloride in water and adjust the pH to 6.8 with 2Mtetrabutylammonium hydroxide. Lyophilize the solution and dissolve theresidue in 10 ml absolute ethanol. Add 1.98 g ethyl2-oxo-4-phenylbutyrate and 7 g. powdered 4A molecular sieves. Add asolution of 357 mg. sodium cyanoborohydride in 3 ml absolute ethanol ata rate of 0.5 ml/hour. After the addition is complete, stir the reactionmixture overnight at room temperature. Filter the reaction mixture, washthe filter cake with ethanol and concentrate the combined filtrate andwashings at aspirator pressure. Dissolve the residue in water and add 20ml ether and 20 ml Dowex 50 (H+). Stir the mixture for 1 hour then drawoff the ether layer.

Extract the aqueous suspension twice more with ether then add theaqueous portion to a column of 100 ml of Dowex 50 (H+). Elute with wateruntil the eluate is neutral then elute with 2% pyridine in water andcollect 600 ml of eluent. Concentrate the eluent in vacuo, dissolve theresidue in water and lyophilize. Isolate1-(1-carboxyethyl)-3-(S)-[(1-ethoxycarbonyl-3-phenylpropyl)amino]perhydroazepin-2-oneas a powder (652 mg.).

NMR: (D₂ O, TSS) δ1 2-1.5 (t+d, 6H); δ1.5-2.6 (m, 8H); δ2.6-3.1 (m, 3H);δ3.2-3.6 (broad, 2H); δ3.9-4.5 (q+m, 4H); δ7.3 (S, 5H).

Mass spectrum: (as monotrimethylsilyl derivative) M+=462; 447 (M--CH₃);389, 373.

Dissolve 110 mg of the ethyl ester in 1 ml 1N sodium hydroxide and heatthe solution at 45° overnight. Chromatograph the reaction mixture on aDowex 50 (H+) column, eluting first with water then with 2% pyridine inwater. Concentrate in vacuo those fractions containing1-(1-carboxyethyl)-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-oneand lyophilize.

Mass Spectrum (as bistrimethylsilyl derivative): M⁺, 506; 491 (M⁺--CH₃); 391 (M⁺ --CO₂ TMS).

EXAMPLE 41-Carboxymethyl-3-(S)-[(1-carboxyethyl)amino]perhydroazepin-2-one

Dissolve 196 mg benzyl pyruvate and 128 mg3-(S)-aminoperhydroazepin-2-one (Adamson, J.Chem. Soc., 1943, 39) in 5ml tetrahydrofuran. Add 0.5 q anhydrous magnesium sulfate then adddropwise over 25 min. a solution of 63 mg sodium cyanoborohydride in 5ml tetrahydrofuran. After completion of the addition, stir the reactionan additional one hour. Filter the reaction and concentrate the filtratein vacuo. Dissolve the residue in ethyl acetate, wash with water andbrine, dry over magnesium sulfate, filter and concentrate the filtratein vacuo to 237 mg of a clear oil. Chromatograph the crude product onsilica gel eluting with ethyl acetate: acetonitrile (95:5). Concentratethose fractions containing3-(S)-[(1-benzyloxycarbonylethyl)amino]perhydroazepin-2-one.

tlc: (silica, ethyl acetate:acetonitrile, 95:5) Rf=0.23.

NMR (CDCl₃, TMS): 1.2-2.3 (m, 10H); δ2.8-3.7 (q+m, 5H); δ5.2 (S, 2H);δ6.8 (broad, 1H), δ7.3 (S, 5H).

Dissolve 320 mg of3-(S)-[(1-benzyloxycarbonylethyl)amino]perhydro-2-azepinone in 10 mltetrahydrofuran and add 0.80 ml of 1.37 M potassium t-amyloxide int-amyl alcohol. After 1-2 min., add a solution of 310 mg benzyliodoacetate in 2 ml tetrahydrofuran in one portion. After 65 hours atroom temperature, pour the reaction into water. Extract with ether, washthe organic phase with water then with brine. Concentrate the ethersolution in vacuo to 440 mg of crude product. Chromatograph the crudeproduct on silica gel eluting with ethylacetate: acetonitrile (95:5).Combine the fractions containing1-benzyloxycarbonylmethyl-3-(S)-[(1-benzyloxycarbonylethyl)amino]perhydroazepin-2-oneand concentrate to a colorless oil.

NMR: (CDCl₃, TMS) δ1.2-2.2 (m+d, 9H); δ3.2 (broad, 2H); δ3.5-4.0 (m,2H); δ4.1-5.0 (m, 2H); δ5.1-5.2 (2S, 4H); δ6.2 (broad, 1H); δ7.3 (S,10H).

Dissolve the diester in aqueous ethanol, and hydrogenate over 10%palladium on charcoal at an initial pressure of 40 psig. Filter thereaction mixture and concentrate the filtrate in vacuo to obtain1-carboxymethyl-3-(S)-[(1-carboxyethyl)amino]perhydroazepin-2-one.

EXAMPLE 51-(1-Carboxyethyl)-3-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one

Dissolve 1.5 g 3,3-dichloroperhydroazepin-2-one [W.C. Francis et al., J.Am. Chem. Soc., 80, 6238 (1958)] in 5 ml dimethylformamide and purge thesolution with nitrogen. Add 6.05 ml of 1.37M potassium t-amyloxide int-amyl alcohol and stir for 5 minutes. Add 2.25 g ethyl 2-iodopropionatethen stir the mixture for 4 days at room temperature. Concentrate thereaction in vacuo, add toluene and concentrate again. Add a secondportion of toluene, filter and concentrate the filtrate in vacuo.Chromatograph the residue on silica gel with hexane:ethyl acetate (7:3).Collect those fractions containing product and isolate 786 mg of3,3-dichloro-1-(1-ethoxycarbonylethyl)perhydroazepin-2-one.

tlc: silica, hexane:ethyl acetate (7:3) Rf=0.5

NMR (CDCl₃, TMS) δ1.1-2.3 (m+t+d, 10H); δ2.5-2.8 (m, 2H); δ3.4-3.7 (m,2H); δ4.2 (q, 2H): δ5.05 (q, 1H).

Saturate 20 ml. methanol with ammonia and add 781 mg of the dichlorocompound and 1 ml water. Hydrogenate the solution over 50 mg 10%palladium on charcoal at an initial pressure of 40 psig. Filter themixture and concentrate the filtrate in vacuo. Triturate the residuewith 50 ml of chloroform, filter and concentrate the filtrate.Chromatograph the residue on silica gel eluting with hexane:ethylacetate (7:3). Collect and concentrate those fractions containing3-chloro-1-(1-ethoxycarbonylethyl)perhydroazepin-2-one as a mixture ofdiastereomers.

Mass spectrum: M+247; 212 (M+--Cl); 202 (M+--C₂ H₅ O).

Dissolve 5.4 g of this monochloro ester and 1.63 g sodium azide in amixture of 5 ml ethanol and 9 ml water. Reflux the mixture overnight,cool, and concentrate in vacuo. Extract the residue into chloroform,filter, dry the filtrate over magnesium sulfate, filter and concentratethe filtrate. Chromatograph the residue on silica gel eluting withhexane:ethyl acetate (9:1). Combine and concentrate those fractionscontaining 3-azido-1-(1-ethoxycarbonylethyl)perhydroazepin-2-one.

Infra red spectrum: γN═N═N, 2100 cm⁻¹ ; γC═O, ester, 1740 cm⁻¹ ; γC═O,amide, 1650 cm⁻¹.

Hydrogenate this azide in aqueous ethanol over 10% palladium oncharcoal. Isolate the3-amino-1-(1-ethoxycarbonylethyl)perhydroazepin-2-one after filtrationand concentration of the filtrate in vacuo.

Hydrolyze this amino ester with 1N sodium hydroxide and isolate3-amino-1-(1-carboxyethyl)perhydroazepin-2-one after chromatography onDowex 50 (H+) using first water then 2% pyridine in water as eluent.

Convert this amino acid to1-(1-carboxy-ethyl)-3-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-oneas described in Example 3.

EXAMPLE 61-(1-Carboxyethyl)-3-[(1-carboxy-3-phenylpropyl)aminoperhydroazepin-2-one

Prepare a solution of chromous chloride in an oxygen-free system byadding a solution of 2.66 g chromium trichloride hexahydrate in 5 ml 5%hydrochloric acid to 654 mg zinc dust. After stirring for 1 hour removeexcess zinc by filtration under nitrogen. Add a solution of3,3-dichloro-1-(1-ethoxycarbonylethyl)perhydroazepin-2-one (prepared asdescribed in Example 5) in 5 ml oxygen-free acetone to the abovefiltrate. After 30 minutes remove the acetone in vacuo, add 15 ml waterand extract the aqueous mixture with three 20 ml portions ofdichloromethane. Concentrate the organic extracts in vacuo andchromatograph the residue on silica gel eluting with hexane/ethylacetate (7:3). Combine fractions containing3-chloro-1-(1-ethoxycarbonylethyl)perhydroazepin-2-one.

tlc (silica, hexane:ethyl acetate, 7:3) Rf: 0.58

Convert this monochloro ester to1-(1-carboxyethyl)-3-[(1-carboxy-3-phenylpropyl)amino]perhydroazein-2-oneas described in Example 5.

EXAMPLE 71-Carboxymethyl-3-(S)-[(1-carboxy-2-phenylethyl)amino]perhydroazepin-2-one

Prepare an aqueous solution of 500 mg3-(S)-amino-1-carboxymethylperhydroazepin-2-one in 5 ml water. Adjustthe pH to 6 with 1N sodium hydroxide solution and add 15 ml water. Reactthis amine with 2.24 g sodium phenylpyruvate monohydrate and 400 mgsodium cyanoborohydride as described in Example 1. Purify 370 mg of thecrude product on an LH-20 column and isoalte 240 mg of1-carboxymethyl-3-(S)-[(1-carboxy-2-phenylethyl)amino]perhydroazepin-2-one.

Mass spectrum (bistrimethylsilyl derivative): M+478; 463 (M+--CH₃); 361[M+CO₂ Si(CH₃)3]

NMR (D₂ O +NaOD): δ1.2-2.0 (m, 6H); δ2.7-3.0 (d, 2H); δ3.0-4.3 (m, 6H);δ7.2 (s, 5H).

EXAMPLE 8 1-Carboxymethyl-3-(S)-[(1-ethoxycarbonyl-4-phenylbutyl)amino]perhydroazepin-2-one

React 1.08 g 3-(S)-amino-1-carboxymethylperhydroazepin-2-onehydrochloride, 5.3 g ethyl 2-oxo-5-phenylpentanoate, 0.49 gtriethylamine and 630 mg sodium cyanoborohydride as described in Example2. Purify the crude product by chromatography on LH 20 and isolate thedesired ester.

NMR (CDCl₃ +TMS): δ1.3 (t, 3H); δ1.4-2.4 (m, 10H); δ2.7 (broad t, 2H);δ2.9-3.9 (m, 5H); δ3.9-4.5 (m, 4H); δ7.3 (s, 5H).

Mass spectrum: M+390; 372 (M+--H₂ O ); 361 (M+--C₂ H₅); 345 (M+OC₂ H₅).

EXAMPLE 91-Carboxymethyl-3-(S)-[(1-carboxy-4-phenylbutyl)amino]perhydroazepin-2-one

Hydrolyze 100 mg1-carboxymethyl-3-(S)-[(1-ethoxycarbonyl-4-phenylbutyl)amino]perhydroazepin-2-onewith sodium hydroxide as described in Example 3. Purify the reactionproduct on Dowex 50 and isolate the diacid.

NMR (D₂ O) δ1.4-2.4 (m, 10H); δ2.8 (t, 2H); δ3.2-4.0 (m, 4H); δ4.0-4.8(m, 3H); δ7.4 (s, 5H).

Mass spectrum: M+362; 344 (M+--H₂ O); 317

(M+--CO₂ H)

EXAMPLE 101-Carboxymethyl-3-(S)-[(1-ethoxycarbonyl-4-methylpentyl)amino]perhydroazepin-2-one

Dissolve 815 mg 3-(S)-amino-1-carboxymethylperhydroazepin-2-onehydrochloride in 5 ml water, adjust the pH to 6 with 1N sodium hydroxideand lyophilize. React this salt with 3.0 g ethyl 2-oxo-5-methylhexanoateand 660 mg sodium cyanoborohydride as described in Example 2. Purify thecrude product by chromatography on LH-20 and isolate 476 mg of pure1-carboxymethyl-3-(S)-[(1-ethoxycarbonyl)-4-methylpentyl)amino]perhydroazepin-2-one.

NMR (D₂ O, Dioxane at δ3.6 int. std.): δ0.7 (d, 6H); δ1.1 (t, 3H);δ1.3-2.2 (m, 11H); δ3.0-3.4 (broad, 2H); δ3.5-4.3 (m, 6H).

Mass spectrum: (monotrimethylsilyl derivative ) M+, 414; 399 (M+--CH₃);341 (M+--CO₂ C₂ H₅)

EXAMPLE 111-Carboxymethyl-3-(S)-[(1-carboxy-4-methylpentyl)amino]perhydroazepin-2-one

Hydrolyze 210 mg of1-carboxymethyl-3-(S)-[(1-ethoxycarbonyl-4-methylpenyl)amino]perhydroazepin-2-onewith sodium hydroxide as described in Example 3. Purify the hydrolyzedester on Dowex 50 (H+) and isolate the diacid.

NMR: (D2O, Dioxane at δ3.6): δ0.7 (d, 6H); δ0.9-2.3 (m, 11H); δ2.9-4.4(m, 6H).

Mass spectrum: M+, 314; 296 (M+--H₂ O); 269 (M+--CO₂ H).

EXAMPLE 123-[t-Butoxycarbonylamino]-1-(1-carboxyethyl)perhydroazepin-2-one

Hydrogenate a solution of 7.6 g N.sup.α -t-butoxycarbonyl-N.sup.ε-benzyloxycarbonyl-L-lysine and 1.81 ml methylpyruvate in 75 ml methanolover 10% palladium on carbon in the standard fashion. After filtrationand concentration isolate N.sup.α -t-butoxy-carbonyl-N.sup.ε-(1-methoxycarbonyl-1-ethyl)lysine.

Dissolve 4.76 g of the lysine derivative, 1.64 g. ofN-hydroxysuccinimide and 3.24 g dicyclohexylcarbodiimide in 250 ml. ofDMF. Store this reaction mixture at 0° C. for two days. Concentrate thereaction in vacuo and dissolve the residue in ethyl acetate. Filter andpurify the product by silica gel chromatography. Isolate the purified3-(S)-t-butoxycarbonylamino-1-(1-methoxycarbonylethyl)perhydroazepin-2-one.

Hydrolyze 2.59 g of this ester in 10 ml methanol and 10 ml H₂ Ocontaining 0.5 ml 50% NaOH. After two hours at room temperature,concentrate the reaction in vacuo, add water, chill to 0°, acidify to pH2 and extract with ethyl acetate. Dry the extracts, filter andconcentrate to obtain the acid.

Apply this acid to a column of milled XAD-2 resin maintained at 50° andelute with 6% CH₃ CN:94% 0.1M NH₄ OH to separate the diastereomers.

Isolate the diastereomer which elutes first from the column (Isomer A)as the ammonium salt. Convert this compound to3-(S)-t-butoxycarbonylamino-1-(1-carboxyethyl)perhydroazepin-2-one bycareful acidification of its aqueous solution. Recrystallize the acidfrom ether-petroleum ether. M.p. 125°-126°. [α]_(Na) ²⁵ °=-33.6° (C=1.8,EtOH). Anal. (C₁₃ H₂₄ NO₅) Calc.: C, 55.98; H, 8.05; N, 9.32. Found: C,55.87; H, 8.09; N, 9.37.

Isolate the diastereomer which elutes second (Isomer B),1-(1-carboxy-1-ethyl)-3-(S)-t-butoxycarbonylaminoperhydroazepin-2-one.NMR (D₂ O, TSS) δ1.3-1.5 (s+d, 12H); δ1.6-2.2 (m, 6H); δ3.3-3.7 (m, 2H);δ4.4 (m, 1H); δ4.9 (q, partially obscured by H₂ O, 1H).

EXAMPLE 131-Ethoxycarbonylethyl-3-(S)-[(1-carboxy-3-phenylpropyl)-amino]perhydroazepin-2-one

3-(S)-t-Butoxycarbonylamino-1-(1-carboxyethyl) perhydroazepin-2-one(Isomer A) (2 g), prepared as in Example 12, was treated with thionylchloride in absolute ethyl alcohol to provide 2.07 g of the3-(S)-amino-1-(1-ethoxycarbonyl)perhydroazepin-2-one hydrochloride. Thismaterial, following careful neutralization with ethanolic sodiumethoxide, was condensed with benzyl 2-keto-4-phenylbutyrate in the samemanner as Example 1, the keto ester having been prepared by thionylchloride treatment of the ketoacid in benzyl alcohol and purified viathe sodium bisulfite addition product. The diastereoisomeric mixtureresulting from the reductive amination (10.6 g) was chromatographed oversilica gel to yield the individual isomers:

Isomer A (first off the column) and isomer B (second off column). Theywere individually hydrogenated over 10% Pd/C in ethanol at atmosphericpressure to afford 299 mg of1-ethoxycarbonylethyl-3-(S)-[(1-carboxy-3-phenyl-1-propyl)amino]perhydroazepin-2-one(Isomer A) and 762 mg of1-ethoxycarbonylethyl-3-(S)-[(1-carboxy-3-phenyl-1-propyl)amino]perhydroazepin-2-one(Isomer B). The first isomer spontaneously changed from an oil to anamorphous solid (m.p. 104°-110° C.); nmr spectrum (CDCl₃) showed thearomatic proton singlet at 7.19 ppm, the ethyl quartet at 4.13 ppm, andthe methyl doublet (1.27 ppm) superimposed on the ethyl triplet (1.21ppm). The nmr spectrum (CDCl₃) of the second isomer showed the aromaticproton singlet at 7.26 ppm, the ethyl quartet at 4.19 ppm, the methyldoublet at 1.37 pm, and the ethyl triplet at 1.23 ppm.

EXAMPLE 141-Carboxymethyl-3-(S)-[(1-carboxy-5-phthalimidyl-1-pentyl)amino]perhydroazepin-2-one

React 2.86 g 3-(S)-amino-1-benzyloxycarbonylmethylperhydroazepin-2-onehydrochloride, prepared from the acid (Example 1) by the method of S.Wang, J. Org. Chem., 42, 1286 (1977), with 13.4 g benzyl2-oxo-5-phthalimidylhexanoate and 1.73 g sodium cyanoborohydride asdescribed in Example 39. Concentrate the reaction mixture in vacuo,dissolve the residue in H₂ O and adjust to pH 1 with 6N HCl. After 5min., adjust to pH 9.5 with 10% Na₂ CO₃ and extract with ethyl acetate.Dry and concentrate the extract to obtain the crude diester.Chromatograph on silica gel using ethyl acetate-hexane (3:2) as eluent.Isolate the diastereomer which elutes second to obtain 2.27 g ofdiester.

Hydrogenate in the standard way 2.6 g of this diester dissolved in 15 mldioxane, 5 ml H₂ O and 0.1 ml. acetic acid using 10% palladium oncharcoal as catalyst. Filter and concentrate the reaction mixture.Chromatograph the residue on LH-20 resin and isolate 1.35 g of thediacid.

tlc, silica gel, CHCl₃ :CH₃ OH--8.2 Rf=0.25.

Mass spectrum: M⁺ 445, m/e 400 (M⁺ --CO₂ H).

EXAMPLE 151-Carboxymethyl-3-(S)-[(5-amino-1-carboxy-1-pentyl)amino]perhydroazepin-2-one

Dissolve 550 mg of the first phthalimido diacid described in Example 14in 5 ml CH₃ OH containing 0.159 ml of N-methylhydrazine. Reflux thesolution for 2 hours, then store at room temperature overnight. Filter,concentrate the filtrate in vacuo, then dissolve the residue in H₂ O.Adjust the pH to 1 with HCl, heat on a water bath for 1 hour, then storethe solution overnight at 4° C. Filter and concentrate the filtrate.Purify the crude product on LH 20 eluting with methanol.

Mass spectrum (tetra-trimethylsilyl deriv) M⁺ 603, m/e 588 (M⁺ --2CH₃);471 [M⁺ --2CH₃ --CO₂ Si(CH₃)₃ ].

In a similar manner, the second phthalimido diacid described in Exmple14 may be converted to1-carboxyethyl-3-(S)-[(5-amino-1-carboxy-1-pentyl)amino]perhydroazepin-2-one.

EXAMPLE 161-[(1-Benzyloxycarbonyl-5-phthalimidyl)pentyl]-3-[(1-carboxy-3-phenylpropyl)amino)]perhydroazepin-2-one

Treat 302 mg of1-[(1-benzyloxycarbonyl-5-phthalimidyl)pentyl]-3-(S)-(t-butyloxycarbonylamino)perhydroazepin-2-one(prepared in Example 19) with 4M HCl in ethyl acetate, strip off thesolvent in vacuo, take up in 20 ml of ethanol, add 471 mg of2-keto-4-phenylbutyric acid, 112 mg of sodium methylate in 10 ml ofethanol, and 2 g of molecular sieves; stir for 1 hour. Then add over a10-hour period a solution of 140 mg of NaBH₃ CN in 15 ml of ethanol.Filter, then add 20 ml of water, 20 ml of ether, and stir for 1 hourwith 15 ml of Dowex 50 (H⁺) ion exchange resin. Separate the water-resinlayer, wash with ether, and charge to the top of a column containing 60ml of Dowwex 50 (H⁺). Wash the column with water, then elute with 4%pyridine in water and methanol. Remove the solvent from the elutedproduct and purify the residue further by chromatography in methanol onLH-20 packing. Strip off the solvent from the appropriate fractions toobtain the desired product as a mixture of isomers. The pmr spectrum isin accord with the structure, and the mass spectrum of silylatedmaterial shows a molecular ion for the monosilylated product at m/e=711.

In the same manner, treatment of the substituted3-aminoperhydrazepin-2-one described above with ethyl4-(3-indolyl)-2-oxo-butyrate in the presence of NaBH₃ CN affords1-[(1-benzyloxycarbonyl-5-phthalimidyl)pentyl]-3-[(1-ethoxycarbonyl-3-(3-indolyl)propyl)amino]perhydroazepin-2-one.

EXAMPLE 171-[(1-Carboxy-5-phthalimidyl)pentyl]-3-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one

Hydrogenate a solution of 604 mg of the benzyl ester from Example 16 in20 ml. of methanol for 20 hours over 0.15 g. of 10% Pd. on carbon.Filter and remove the solvent to obtain the desired diacid. The pmr isin accord with the structure and confirms the loss of the benzyl ester.The mass spectrum of silylated material shows molecular ions for thedisilylated product at m/e=693 and for the trisilylated product atm/e=765.

Similarly, catalytic hydrogenation of1-[(1-benzyloxycarbonyl-5-phthalimidyl)pentyl]-3-[(1-ethoxycarbonyl-3-(3-indolyl)propyl)amino]perhydroazepin-2-one,followed by the usual basic hydrolysis affords1-[(1-carboxy-5-phthalimidyl)pentyl]-3-[(1-carboxy-3-(3-indolyl)propyl)amino]perhydroazepin-2-one.

EXAMPLE 181-[(1-Carboxy-5-amino)pentyl]-3-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one

Treat a solution of 489 mg. of the phthalimide of Example 17 in 10 ml.of methanol and 15 ml. of water with 260 mg of hydrazine hydrate undernitrogen at 70° for three hours. Cool, strip off the volatiles in vacuo,dissolve in 2 ml. of methanol, and filter off the phthalhydrazide.Chromatograph on LH-20 in methanol, and strip off the solvent from theappropriate fractions in vacuo to obtain the product.

The pmr spectrum is in accord with the structure and the mass spectrumof silylated material shows a peak at m/e=635 for the trisilylatedproduct and at m/e=707 for the tetrasilylated product.

In a similar manner, treatment of1-[(1-carboxy-5-phthalimidyl)pentyl]-3-[(1-carboxy-3-(3-indolyl)propyl)amino]perhydroazepin-2-onewith hydrazine hydrate affords1-[(1-carboxy-5-amino)pentyl]-3-[(1-carboxy-3-(3-indolyl)propyl)amino]perhydroazepin-2-one.

EXAMPLE 191-[(1-Benzyloxycarbonyl-5-phthalimidyl)pentyl]-3-(S)-(t-butoxycarbonylamino)perhydroazepin-3-one

React 80.6 g. of 2-benzyloxycarbonyl-1,3-dithiane with 98.3 g. ofN-4-bromobutyl-phthalimide in 130 ml. of DMF under nitrogen, by adding15.2 g. of 50% sodium hydride emulsion (prewashed with petroleum ether)in 380 ml. of benzene over 65 minutes, keeping cold in an ice bath. Stirovernight at room temperature, add water and benzene, separate, washwith water and concentrate the organic layer to dryness in vacuo. Cleavethe dithiane with N-bromosuccinimide in acetone followed by aqueous 5%sodium bicarbonate, concentrate, extract into 1:1 methylenechloride:hexane. Purify the ketoester by chromatography on silica inethyl acetate:hexane 1:1.

Condense 5.0 g. of the keto-ester with 674 mg. of α-t-Boc-L-lysine inanhydrous ethanol in the presence of 5.4 g. of powdered 4A-molecularsieves under nitrogen, employing 600 mg. of sodium cyanoborohydrideadded over a 6-hour period by the method previously described. Purifythe crude product by chromatography on LH-20 in methanol. Convert to thecaprolactam by treatment with one equivalent of N-hydroxysuccinimide anda small excess of dicyclohexylcarbodiimide in methylene chloride at 0°;the reaction requires several days. Filter, concentrate to dryness, andpurify the crude product by chromatography on silica gel with 7:3hexane:ethyl acetate as eluant. The pmr of the product is consistentwith its structure, and the mass spectrum has a molecular ion atm/e=577.

EXAMPLE 201-[1-Carboxy-2-(3-indolyl)ethyl]-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one

Methyl 3-[3-indolyl]-2-oxopropionate (1.09 g) and α-t-Boc-L-lysine(0.246) are dissolved in ethanol solvent containing powdered 4 Åmolecular sieves (1.87 g). A solution of sodium cyanoborohydride (0.189g) in ethanol is added at room temperature over six hours. When reactionis complete, the solvent is removed and the residue is partitionedbetween ether and water. The aqueous layer is isolated and pH adjustedto 3.6. The crude product is extracted into ethyl acetate and purifiedby LH-20 chromatography. Ring closure to3-(S)-t-butoxycarbonylamino-1-[1-carbomethoxy-2-(3-indolyl)ethyl]perhydroazepin-2-oneis carried out as described in Example 3. Saponificaton of the methylester and subsequent formic acid treatment to remove thet-butoxycarbonyl protecting group yields3-(S)-amino-1-[1-carboxy-2-(3-indolyl)ethyl]perhydroazepin-2-one.2-Oxo-4-phenylbutyric acid and this caprolactam are condensed in thepresence of sodium cyanoborohydride to yield1-[1-carboxy-2-(3-indolyl)ethyl]-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one.The silylated mass spectrum shows a parent ion at 693 m/e [3TMS+477MWt], and loss of CH₃ =678 m/e is observed.

EXAMPLE 211-[1-Carboxy-2-(4-hydroxyphenyl)ethyl]-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one

Methyl 3-(p-phydroxyphenyl)-2-oxopropionate and α-t-Boc-L-lysine arecondensed in the presence of sodium cyanoborohydride as described inExample 19. Subsequent ring closure, saponification of methyl ester, andremoval of the t-butoxycarbonyl group with formic acid gives3-(S)-amino-1-[1-carboxy-2-(4-hydroxyphenyl)ethyl]perhydroazepin-2-one.The caprolactam and 2-oxo-4-phenylbutyric acid are condensed in thepresence of sodium cyanoborohydride to yield1-[1-carboxy-2-(4-hydroxyphenyl)ethyl]-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one.

EXAMPLE 221-[1-Carboxy-2-phenylethyl]-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one

Methyl 2-oxo-3-phenylpropionate and α-t-Boc-L-lysine are condensed inthe presence of sodium cyanoborohydride as described in Example 19.Subsequent ring closure to3-(S)-t-butoxycarbonylamino-1-[1-carbomethoxy-2-phenylethyl]perhydroazepin-2-oneis carried out as described in Example 3. Saponification of the methylester followed by removal of the t-butoxycarbonyl group affords3-(S)-amino-1-[1-carboxy-2-phenylethyl]perhydroazepin-2-one. Thecaprolactam and 2-oxo-4-phenylbutyric acid are condensed in the presenceof sodium cyanoborohydride to yield1-[1-carboxy-2-phenylethyl]-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one.

EXAMPLE 231-(1-Ethoxycarbonylethyl)-3-(S)-[(1-ethoxycarbonyl-3-phenylpropyl)amino]perhydroazepin-2-one

A solution of1-(1-carboxyethyl)-3-(S)-[(1-ethoxycarbonyl-3-phenylpropyl)amino]perhydroazepin-2-one(2.94 g.), a diastereoisomeric mixture prepared as in Example 13 fromIsomer A of Example 12, with 40 ml. of ethanol was cooled to 0° andsaturated with hydrogen chloride. After standing overnight at roomtemperature the solution was concentrated under vacuum. Dissolution inwater, adjustment to pH 7, extraction with ether and concentration gaveproduct as a colorless oil, weight 2.87 g. Tlc on silica gel indicatedthe presence of two diastereomers. If desired, the isomers may beseparated by chromatography on silica gel and elution with hexane-ethylacetate.

EXAMPLE 241-(1-Benzyloxycarbonylethyl)-3-(S)-[(1-ethoxycarbonyl-3-phenylpropyl)amino]perhydroazepin-2-one

3-(S)-t-Butoxycarbonylamino-1-(1-carboxyethyl) perhydroazepin-2-one(Isomer A), prepared in Example 12, is coverted to1-(1-benzyloxycarbonylmethyl)-3-(S)-t-butoxycarbonylaminoperhydroazepin-2-oneby the method of Wang, et al., J. Org. Chem., 42, 1286 (1977), NMR:(CCl₄, TMS) δ1.3 (d, 3H); δ1.38 (S, 9H); δ1.7 (m, 6H); δ3.2 (broad, 2H);δ4.2 (m, 1H); 5.1 (q+s, 3H); δ5.8 (d, 1H); 7.2 (S, 5H).

[α]_(D) ²⁵ =-23.8 (C=2.0, EtOH).

Removal of the t-butoxycarbonyl qroup in 4M HCl in ethyl acetate affords3-(S)-amino-1-(1-benzyloxycarbonylethyl)perhydroazepin-2-one. NMR (D₂ O,dioxane=3.67) δ1.2-2.1 (d+m, 9H); δ3.3 (broad, 2H); δ4.2 (m, 1H);δ4.6-5.0 (q+s, 3H); δ7.2 (s, 5H).

[α]_(D) ²⁵ =-26.3 (C=2.2, EtOH).

A solution of 850 mg of this aminolactam, 2.14 g ethyl2-oxo-4-phenylbutyrate and 267 mg sodium acetate is prepared in 8 mlethanol. A solution of 490 mg sodium cyanoborohydride in 3 ml ethanol isadded over 3.5 hr and stirring is continued overnight. The reaction isfiltered and concentrated and the residue is partitioned between ethylacetate and 5% sodium bicarbonate. The organic phase is washed withbrine, dried and concentrated. The crude product is purified bychromatography over silica gel eluting with 3:2 hexane:ethylacetateaffording the two diastereomers of1-(1-benzyloxycarbonylethyl)-3-(S)-(1-ethoxycarbonyl-3-phenylpropyl)aminoperhydroazepin-2-one.Isomer A (elutes first): [α]_(D) ²⁵ =-26.6 (C=2.0, EtOH). NMR (CCl₄,TMS): δ1.0-2.0 (t+d+m, 14H) δ2.5-3.4 (m, 7H); δ4.1 (q, 2H); δ5.0-5.2(s+m, 3H); δ7.1 (s, 5H); δ7.3 (s, 5H).

Isomer B (elutes second, major isomer): [α]_(D) ²⁵ =-40.2 (C=2.0, EtOH).

NMR (CC14, TMS): δ1.0-2.1 (t+d+m, 14H); δ2.1-3.0 (m, 4H); δ3.1-3.7 (m,3H); δ1 (q, 2H); 5.0-5.2 (q+s, 3H); δ7.1 (s, 5H);.7.25 (s, 5H).

EXAMPLE 25 1-(1-Carboxyethyl)-3-[(3-phenyl-1-carboxamido-1-propyl)amino]perhydroazepin-2-one, ammonium salt

A solution of 260 mg of1-(1-carboxyethyl)-3-[(1-carbethoxy-3-phenyl-1-propyl)amino]perhydroazepin-2-onein 5 ml. of ethanol contained in a pressure vessel was cooled in an icebath and saturated with ammonia gas at atmospheric pressure. The vesselwas closed and kept at room temperature for 72 hours, at which time thereaction was complete as judged by thin layer chromatography. Thesolvent was removed by evaporation, and the product was lyophilized fromwater. Yield 200 mg.

Tlc: (silica plates, butanolacetic acidwaterethyl acetate 1:1:1:1)single spot, R_(f) =0.47.

EXAMPLE 26 1-(1-Carboxamidoethyl)-3-[(3-phenyl-1-carboxy-1-propyl)amino]perhydroazepin-2-one, ammonium salt

This compound was made from the corresponding ethyl ester by a methodsimilar to that described in the foregoing Example.

Tlc: (silica plates, butanol-acetic acid-water-ethyl acetate 1:1:1:1)single spot, R_(f) =0.60.

EXAMPLE 271-Carboxymethyl-3-[(1-carboxy-3-phenyl-1-propyl)amino]-7-methylperhydroazepin-2-one

React 31.5 g. PCl₅ in 100 ml. benzene with 6.35 g. 2-methylcyclohexanoneoxime following the procedure of Francis, J. Am. Chem. Soc., 80, 6238(1958) to obtain 3,3-dichloro-7-methylperhydroazepin-2-one. (m.p.132.5°-134°).

Add a solution of 6.73 g. of this lactam in 35 ml. THF to a suspensionof 0.86 g. NaH in 25ml. THF over 20 min. When hydrogen evolution ceases,add 8.70 g. t-butyl iodoacetate in 20 ml. THF over 30 min. When tlcindicates the reaction to be complete, add 50 ml. H₂ O, separate theorganic phase and wash with saturated (NH₄)₂ SO₄ solution. Back wash thecombined aqueous phases with ether, combine all organic phases and dryover Na₂ SO₄. Filter and concentrate the filtrate in vacuo to obtain1-t-butoxycarbonylmethyl-3,3-dichloro-7-methylperhydroazepin-2-one.

Nmr (CDCl₃, TMS): δ1.35 (d, 3H); δ1.45 (s, 9H); δ1.7-2.2 (m, 4H);δ2.6-2.9 (m, 2H); δ3.8-4.4 (m, 3H).

Hydrogenate a solution of 1.55 g. of this lactam in 10 ml. dioxane and 5ml. H₂ O containing 200 mg. MgO using 10% palladium on charcoal ascatalyst. Filter the reaction, concentrate the filtrate in vacuo andpartition the residue between H₂ O and ether. Dry and concentrate theether. Dry and concentrate the ether layer to obtain1-t-butoxycarbonylmethyl-3-chloro-7-methylperhydroazepin-2-one as anoil.

Prepare an analytical sample by silica gel chromatography. Calc. (C₁₃H₂₂ ClNO₃): C, 56.62; H, 8.04; N, 5.08. Found: C, 56.75; H, 8.18; N,4.89.

Heat a solution of 7.0 g of this monochlorolactam and 3.10 g sodiumazide in 70 ml DMF at 100° for 20 hr. Concentrate the reaction in vacuoand partition the residue between water and ether. Dry the ether layerand concentrate to the crude product. Chromatograph the crude product onsilica gel using 7:3 hexane:ethyl acetate to obtain pure3-azido-1-t-butoxycarbonylmethyl-7-methylperhydroazepin-2-one.

Ir: .sub.γN.sbsb.3, 2120 cm⁻¹ ; .sub.γCO, 1750 cm⁻¹, 1680 cm⁻¹.

Hydrogenate 5.1 g of this azide in 75 ml EtOH using 10% palladium oncharcoal catalyst. Concentrate the filtered reaction mixture in vacuo toobtain the semicrystalline product as a mixture of diastereomers.Fractionally crystallize the crude product from ether-ethyl acetate toobtain the pure major diastereomer of3-amino-1-t-butoxycarbonylmethyl-7-methylperhydroazepin-2-one. m.p.117.5°-118°.

Obtain the minor diastereomer by chromatography of the residue from themother liquors.

Hydrogenate a solution of 512 mg of the pure major diastereomer of3-amino-1-t-butoxycarbonylmethyl-7-methylperhydroazepin-2-one, 618 mgethyl 2-oxo-4-phenylbutyrate and 120 mg acetic acid in 20 ml ethanolusing 10% palladium on charcoal as catalyst. Concentrate the filteredreaction mixture in vacuo and obtain the crude product. Purify the crudeproduct by chromatography on silica gel using 1:1 ethyl acetate:hexaneand isolate two diastereomeric racemates of1-t-butoxycarbonylmethyl-3-[(1-ethoxycarbonyl-3-phenylpropyl)-amino]-7-methylperhydroazepin-2-one.

Racemate A (first to elute). Anal. Calc. (C₂₅ H₃₈ N₂ O₅): C, 67.24; H,8.58; N, 6.27. Found: C, 67.30 H, 8.71; N, 6.03. Mass spectrum: M+=446;m/e: 389 (M⁺ --C₄ H₉); 373 (M⁺ --C₂ H₅ CO₂); 317 (base, 373 --C₄ H₈).

Racemate B (second to elute). Anal. Calc. (C₂₅ H₃₈ N₂ O₅): C, 67.24; H,8.58; N, 6.27. Found: C, 66.82; H, 8.55; N, 6.10. Mass spectrum: same asabove.

Dissolve 380 mg. of racemate B in 2 ml. trifluoroacetic acid and storethe solution for 2 hours at room temperature. Concentrate the reactionin vacuo, treat the residue with water and reconcentrate. Isolate1-carboxymethyl-3-[(1-ethoxycarbonyl-3-phenylpropyl)amino]-7-methylperhydroazepin-2-oneas the trifluoroacetate salt, m.p. 142°-145°.

Mass spectrum: M⁺ 390, m/e: 373 (M⁺ --OH); 362 (M⁺ --C₂ H₄); 331 (M⁺--CH₂ CO₂ H); 317 (M⁺ --CO₂ C₂ H₅).

Repeat the procedure on racemate A to obtain the isomeric monoester.

Dissolve 200 mg. of racemate B monoester trifluoroacetate in 2.5 ml. 1NNaOH and store the solution for 18 hr. at room temperature. Apply thereaction mixture to a column of Dowex 50 (H⁺), elute first with H₂ O andthen with 5% pyridine. Combine and concentrate the appropriate fractionsand isolate1-carboxymethyl-3-[(1-carboxy-3-phenylpropyl)amino]-7-methylperhydroazepin-2-one(racemate B), m.p. 215°-217° Dec.

Mass spectrum: M⁺ 362; m/e: 344 (M⁺ --H₂ O), 318 (M⁺ --CO₂); 317 (M⁺--CO₂ H).

Treat the monoester as described above and isoalte the diacid (racemateA).

Mass spectrum: M⁺ 362; m/e: 344 (M⁺ --H₂ O); 318 (M⁺ --CO₂); 317 (M⁺--CO₂ H).

Similarly, treat the minor diastereomer of3-amino-1-t-butoxycarbonylmethyl-7-methylperhydroazepin- 2-one asdescribed above and isolate a second pair of diacids which arediastereomeric racemates.

The isomers of1-carboxymethyl-3-[(1-ethoxycarbonyl-3-phenylpropyl)amino]-7-methylperhydroazepin-2-one may each be converted to the corresponding diethylesters by the method described in Example 22.

EXAMPLE 281-(1-Carboxyethyl)-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one

The mixture of diastereomers of1-(1-ethoxycarbonylethyl)-3-(S)-[(1-ethoxycarbonyl-3-phenylpropyl)amino]perhydroazepin-2-one (Example 23) is separated by chromatographyon silica gel with hexane:ethyl acetate (7:3). Isolate two isomers ofthe diester. Isomer A (first to elute). NMR (CCl₄, TMS): 1.25 (m, 9H);δ1.4-2.2 (m, 8H); δ2.7 (m, 2H); δ3.2 (m, 4H); δ3.5 (s, 1H); δ4.2 (2xq,4H); δ5.2 (q, 1H); δ7.2 (s, 5H). Isomer B. NMR (CCl₄, TMS): δ1.15 (t,9H); δ1.4-2.2 (m, 8H); δ2.7 (m, 2H); δ3.1-3.7 (m, 4H); δ3.8 (s, 1H);δ4.1 (q, 4H); δ5.1 (q, 1H); δ7.2 (s, 5H).

Each of the isomeric esters is hydrolyzed in dilute sodium hydroxide.The hydrolysate is chromatographed over acidic ion exchange resineluting with 5% pyridine in water. Concentration of the appropriatefractions affords the respective isomers of1-(1-carboxyethyl)-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one. Isomer A[α]_(Na) ²⁵ =37.0 (C=2.56, 0.1N NaOH) NMR(D₂ O+NaOH, dioxane=δ3.8): δ1.33 (d, 3H, J=7 hz); δ1.4-2.3 (m, 8H);δ2.6-3.0(m, 2H); δ3.0-3.6(m, 4H); caδ4.8 (obscured by H₂ O); δ7.4 (S,5H) Isomer B: [α]_(Na) ²⁵ =-56.7° (C=2.82, 0.1N NaOH). NMR (D₂ O+NaOD,dioxane=3.8), δ1.3 (d, 3H, J=7 hz); δ1.4-2.3 (m, 8H); 2.5-2.9 (m, 2H);δ3.1-3.8 (m, 4H); caδ0.48 (obscured by H₂ O); δ7.3 (s, 5H).

EXAMPLE 291-(1-Carboxy-1-methylethyl)-3-(S)-[(1-carboxy-3-phenylpropyl)amino]perhydroazepin-2-one

From 2-S-amino-6-hydroxyhexanoic acid [prepared according to Berlinguetand Gandry, J. Biol. Chem., 198, 765 (1952)] prepare theN-t-butoxycarbonyl derivative using the procedure of Otuska et al.,Bull. Chem. Soc. Japan, 39, 1171 (1966)]. Convert this protectedderivative to the O-p-toluenesulfonate benzyl ester [D. Theodoropouloset al., Biochemistry 6, 3927 (1967)]. Heat this diester with excessethyl 2-aminoisobutyrate in toluene. Purify the crude reaction productchromatographically on silica gel and isolate N.sup.α-t-butoxycarbonyl-N.sup.ε -(2-ethoxycarbonyl-2-propyl)-lysine benzylester. Remove the benzyl ester using standard hydrogenolysis conditionsand cyclize the resulting acid using dicylohexylcarbodiimide andN-hydroxysuccinimide as described in Example 3. After purification ofthe lactam, react it with ethyl 2-oxo-4-phenylbutyrate and hydrogen asdescribed in Example 1. Purify the resulting diester by chromatographyand isolate the diastereomers. Hydrolyze each of the diastereomericdiesters with 1M NaOH and purify the diacids by ion exchangechromatography.

EXAMPLE 301-(1-Carboxyethyl)-3-(S)-(1-ethoxycarbonyl-3-phenylpropyl)aminoperhydroazepin-2-one

The diastereomers described in Example 24 are catalytically dibenzylatedover palladium on carbon in aqueous dioxane to afford the respectivediastereomers of1-(1-carboxyethyl)-3-(S)-(1-ethoxycarbonyl-3-phenylpropyl)aminoperhydroazepin-2-one.

Isomer A: [α]_(D) ²⁵ =-22.3° (C=2.2, EtOH); m.p. 132-134. NMR (CDCl₃,TMS): δ1.1-1.5 (d=t, 6H); 1.5-2.3 (m, 8H); 2.5-3.0 (m, 2H); 3.35 (m,4H); 4.2 (q, 2H); 5.1 (q, 1H); 6.65 (s, 2H); 7.2 (s, 5H).

Anal. (C₂₁ H₃₀ N₂ O₅): Calc.: C, 64.59; H, 7.74; N, 7.18. Found: C,64.20; H, 7.74; N, 6.70.

Isomer B: [α]_(D) ²⁵ =-39.9 (C=3.1, EtOH): m.p. 110-113 (EtOAc). NMR(CDCl₃, TMS): δ1.2-1.5 (d=t, 6H); 1.5-2.3 (m, 8H); 2.6-2.9 (m, 2H);3.2-3.7 (m, 4H); 4.2 (q, 2H); 5.1 (q, 1H); 7.2 (s, 7H).

Anal. (C₂₁ H₃₀ N₂ O₅): Calc.: C, 64.59; H, 7.74; N, 7.18. Found: C,64.18; H, 7.74; N, 6.93.

EXAMPLE 31 Diesters of Formula I derived from3-(S)-amino-1-(1-ethoxycarbonylethyl)perhydroazepin-2-one

3-(S)-Amino-1-(1-ethoxycarbonylethyl)perhydroazepin-2-one (prepared asdescribed in Examples 12 and 13 from Isomer A) is reductively condensedwith the following α-ketoesters (Table I) in place of ethyl2-oxo-4-phenylbutyrate using the palladium on charcoal method asdescribed in Example 27. Work up and purification as described in thisexample affords the corresponding diesters listed in Table II.

Alternatively, sodium cyanoborohydride may be used in the reductivecondensation as described in Example 24.

EXAMPLE 32 Diacids of Formula I derived from3-(S)-amino-1-(1-carboxyethyl)perhydroazepin-2-one

Saponification of the diesters listed in Table II using the proceduredescribed in Example 3 including purification gives the products ofFormula I described in Table II wherein R, R², R⁵, R⁶ =H, R³ =CH₃, R⁴=OH.

Alternatively, reductive condensation of3-(S)-amino-1-(1-carboxyethyl)perhydroazepin-2-one (Example 12) with theα-ketoacids listed in Table III following the procedure described inExample I affords the products of Formula I described above.

EXAMPLE 33 Monoesters of Formula I derived from3-(S)-amino-1-(1-carboxyethyl)perhydroazepin-2-one

Reductive condensation of the α-ketoesters listed in Table I with3-(S)-amino-1-(1-carboxyethyl)perhydroazepin-2-one (Isomer A) asdescribed in Example 3 affords the products of Formula I listed in TableII wherein R², R⁵, R⁶ =H and R³ =CH₃, R⁴ =OH.

EXAMPLE 34 Monoesters of Formula I derived from3-amino-1-carboxymethyl-7-methylperhydroazepin-2-one

The major diastereomer of3-amino-1-t-butoxycarbonylmethyl-7-methylperhydroazepn-2-one (Example27) is reductively condensed with the α-ketoesters listed in Table Iusing either the palladium catalyzed reduction method (Example 27) orthe sodium cyanoborohydride procedure (Example 24). Chromatographicpurification of the products followed by removal of the t-butyl ester(Example 27) affords the compounds of Formula I listed in Table IIwherein R² =CH₃ ; R³, R⁵, R⁶ =H and R⁴ =OH.

EXAMPLE 35 Diacids of Formula I derived from3-amino-1-carboxymethyl-7-methylperhydroazepin-2-one

Saponification of the monoesters prepared in Example 34 using theprocedure described in Example 3, including purification, gives theproducts of Formula I described in Table II wherein R³, R⁵, R⁶ =H; R²=CH₃ ; R, R⁴ =OH.

Alternatively, the t-butyl ester of the major diastereomer of3-amino-1-t-butoxycarbonylmethyl-7-methylperhydroazepin2-one may becleaved with trifluoroacetic acid to afford3-amino-1-carboxymethyl-7-methylperhydroazepin-2-one. Reductivecondensation of this compound with the α-ketoacids listed in Table IIIfollowing the procedure described in Example I affords the products ofFormula I described above.

EXAMPLE 36 Monoesters of Formula I derived from3-amino-1-carboxymethyl-7-methylperhydroazepin-2-one

Reductive condensation of the α-ketoesters listed in Table I with3-amino-1-carboxymethyl-7-methylperhydroazepin-2-one (Example 35) usingthe conditions described in Examples 24 or 27 affords the products ofFormula I listed in Table II wherein R³, R⁵ =H, R² =CH₃, R⁴ =OH.

                  TABLE I                                                         ______________________________________                                        α-Ketoesters                                                            ______________________________________                                        a.       Benzyl    2-oxo-4-phenylbutyrate                                     b.       Ethyl     4-p-chlorophenyl-2-oxobutyrate                             c.       Ethyl     4-(3-indolyl)-2-oxobutyrate                                d.       Ethyl     2-oxo-4-(2-thienyl)butyrate                                e.       Ethyl     2-oxo-4-(2-naphthyl)butyrate                               f.       Ethyl     4-p-hydroxyphenyl-2-oxobutyrate                            g.       Ethyl     phenoxypyruvate                                            h.       Ethyl     2-oxo-5-phenylpentanoate                                   i.       Ethyl     4-p-methoxyphenyl-2-oxobutyrate                            j.       Ethyl     5-methyl-2-oxohexanoate                                    k.       Benzyl    2-oxo-6-phthalimidohexanoate                               ______________________________________                                    

                  TABLE II                                                        ______________________________________                                        Products of Formula I                                                         (R.sub.2, R.sub.5 = H; R.sub.3 = CH.sub.3)                                    R               R.sub.1       R.sub.4                                         ______________________________________                                        l.      benzyloxy   phenylethyl   ethoxy                                      m.      ethoxy      p-chlorophenethyl                                                                           ethoxy                                      n.      ethoxy      3-indolylethyl                                                                              ethoxy                                      o.      ethoxy      2-thienylethyl                                                                              ethoxy                                      p.      ethoxy      2-naphthylethyl                                                                             ethoxy                                      q.      ethoxy      p-hydroxyphenethyl                                                                          ethoxy                                      r.      ethoxy      phenoxymethyl ethoxy                                      s.      ethoxy      3-phenylpropyl                                                                              ethoxy                                      t.      ethoxy      p-methoxyphenethyl                                                                          ethoxy                                      u.      ethoxy      3-methylbutyl ethoxy                                      v.      benzyloxy   4-phthalimidobutyl                                                                          ethoxy                                      w.      benzyloxy*  4-aminobutyl  ethoxy                                      ______________________________________                                         *after hydrazinolysis                                                    

                  TABLE III                                                       ______________________________________                                        α -Ketoacids                                                            ______________________________________                                        x.         2-oxo-4-phenylbutyric acid                                         y.         4p-chlorophenyl-2-oxobutyric acid                                  z.         4-(3-indolyl)-2-oxobutyric acid                                    aa.        2-oxo-4-(2-thienyl)butyric acid                                    bb.        2-oxo-4-(2-naphthyl)butyric acid                                   cc.        4-p-hydroxyphenyl-2-oxobutyric acid                                dd.        phenoxypyruvic acid                                                ee.        2-oxo-5-phenylpentanoic acid                                       ff.        4-p-methoxyphenyl-2-oxobutyric acid                                gg.        5-methyl-2-oxohexanoic acid                                        hh.        2-oxo-6-phthalimidohexanoic acid                                   ______________________________________                                    

EXAMPLE 37 Monoesters of Formula I derived from3-(S)-amino-1-(1-carboxyethyl)perhydroazepin-2-one

Reaction of 3-(S)-amino-(1-1-benzyloxycarbonylethyl)perhydroazepin-2-one(Example 24) or3-(S)-amino-1-(1-ethoxycarbonylethyl)perhydroazepin-2-one (Example 13)with some of the ketoacids from Table III using the procedure of Example2 affords the products of Formula I(R², R⁵ =H; R³ =CH₃, R=OH) listed inTable IV.

                  TABLE IV                                                        ______________________________________                                        Monoesters of Formula I                                                                R.sup.1       R.sup.4                                                ______________________________________                                        ii.        p-chlorophenethyl                                                                             benzyloxy                                          jj.        2-naphthylethyl benzyloxy                                          kk.        3-methylbutyl   benzyloxy                                          ll.        4-aminobutyl*   benzyloxy                                          mm.        phenethyl       ethoxy                                             nn.        phenethyl       benzyloxy                                          ______________________________________                                         *after hydrazinolysis                                                    

EXAMPLE 38 Monoesters of Formula I derived from3-amino-1-carboxymethyl-7-methylperhydroazepin-2-one

Reaction of the major isomer of3-amino-1-t-butoxymethyl-7-methylperhydroazepin-2-one with benzylalcohol and thionyl chloride yields3-amino-1-benzyloxymethyl-7-methylperhydroazepin-2-one hydrochloride,which after treatment with base, yields the free amino ester. Reactionof this amino ester as described in Example 37 affords the products ofFormula I (R³, R⁵, R⁶ =H; R² =CH₃ ; R=OH) listed in Table IV.

Alternatively, use of ethanol in place of benzyl alcohol affords thecorresponding ethyl esters listed in Table IV and described above.

EXAMPLE 391-(1-Benzyloxycarbonylethyl)-3-(S)-(1-carboxy-3-phenylpropyl)aminoperhydroazepin-2-one

A solution of 490 mg sodium cyanoborohydride in 3 ml ethanol is addedover 2.5 hrs to a solution of 2.43 g t-butyl 2-oxo-4-phenylbutyrate, 850mg 1-(1-benzyloxycarbonylethyl)-3-(S)-aminoperhydroazepin-2-onehydrochloride (from Isomer A, Example 24) and 267 mg sodium acetate in10 ml ethanol. The reaction is stirred at room temperature overnight,filtered and concentrated. The residue is partitioned between ethylacetate and 5% sodium bicarbonate. After drying, concentration of theorganic phase affords a residue which is chromatographed over silica gelwith hexane-ethyl acetate (7:3) giving the pure diastereomers of1-(1-benzyloxycarbonylethyl)-3-(S)-(1-t-butoxycarbonyl-3-phenylpropyl)aminoperhydroazepin-2-one.

Isomer A (elutes first): [α]_(Na) ²⁵ =-24.6° (C=2, EtOH)

Isomer B (elutes second): [α]_(Na) ²⁵ =-31.1° (C=2, EtOH).

Treatment of each of these isomers with HCl-EtOAc affords1-(1-benzyloxycarbonylethyl)-3-(S)-(1-carboxy-3-phenylpropyl)aminoperhydroazepin-2-onehydrochloride.

Isomer A: [α]_(Na) ²⁵ =-51.4° (c=2, EtOH).

Isomer B: [α]_(Na) ²⁵ =-15.7° (c=2, EtOH).

NMR (DMSO-d₆): δ1.2-2.1 (m+d, J=7 hz); δ2.4-2.9 (m, partially obscuredby DMSO); δ3.0-4.0 (m); δ4.9 (q, J=7 hz); δ5.1 (s); δ7.0 (broad), δ7.2(s); δ7.35 (s).

EXAMPLE 401-Carboxymethyl-3-(1-carboxy-3-phenylpropyl)amino-7-phenylperhydroazepin-2-one

To a solution of 25 g phosphorus pentachloride in 220 ml CH₂ Cl₂ kept at0° is added a solution of 22 g 7-phenylcaprolactam and 18.9 g pyridinein 220 ml CH₂ Cl₂. Portionwise addition of 45.1 gphenyltrimethylammonium tribromide is followed by allowing the reactionmixture to reach room temperature. After 3 hours, the reacton mixture ispoured into ice water and extracted with CH₂ Cl₂. The organic phase iswashed with 5% aqueous sodium bisulfite. After drying and concentration,the crude residue is purified by chromatography over silica gel elutingwith ethyl acetate:hexane (2:3). Concentration of the appropriatefractions affords 16.3 g. 3-bromo-7-phenylperhydroazepin-2-one as amixture of diastereomers.

A solution of 15.5 g of this lactam and 14.7 t-butyl iodoacetate in 150ml tetrahydrofuran is added dropwise to a slurry of 1.45 g sodiumhydride in 20 ml tetrahydrofuran. After 3 hr at room temperature thereaction is quenched by the addition of 15 ml sat. NH₄ Cl solution. Themixture is filtered and concentrated and the residue is partitionedbetween CHCl₃ and H₂ O. The crude product is obtained after drying andconcentrating the CHCl₃ solution. Chromatography over silica gel withhexane: ethyl acetate (4:1) affords two isomers of3-bromo-1-t-butoxycarbonylmethyl-7-phenylperhydroazepin-2-one: isomer A(minor, elutes first), and isomer B (major, elutes second).

A solution of 20 g of isomer B and 7.69 g lithium azide in 100 mldimethylformamdie is heated at 80° overnight. After concentration, theresidue is partitioned between water and ethyl acetate. The organicphase is dried and concentrated to afford3-azido-1-t-butoxycarbonylmethyl-7-phenylperhydroazepin-2-one which maybe recrystallized from ethyl acetate-hexane.

NMR (CDCl₃, TMS): δ1.45 (s, 9H); δ1.6-2.7 (m, 6H); δ3.3 (d, 1H, J=17hz); δ4.0 (d, 1H, J=17 hz); δ4.4 (broad m, 1H); δ4.8 (broad d, 1H);δ7.25 (s, 5H).

A solution of 8.95 g of this azide in 75 ml ethanol is hydrogenated over2 g 10% Pd-C at 45° C. for 5 hr. The soluion is then filtered andconcentrated to afford 8.3 g3-amino-1-t-butoxycarbonylmethyl-7-phenylperhydroazepin-2-one. NMR(CDCl₃, TMS): δ1.4 (s, 9H); δ1.7-2.5 (m+s, 8H); δ3.4 (d, 1H, J=17 hz);δ3.95 (d, 1H, J=17 hz); δ4.0 (broad m, 1H); δ4.95 (broad d, 1H); δ7.3(s, 5H).

A solution of 3.8 g of this amine, 3.7 g ethyl 2-oxo-4-phenylbutyrateand 0.68 ml acetic acid in 50 ml ethanol is hydrogenated and the isomersseparated as described in Example 27 to afford1-t-butoxycarbonylmethyl-3-(1-ethoxycarbonyl-3-phenylpropyl)amino-7-phenylperhydroazepin-2-one:

Isomer A (elutes first) and isomer B (elutes second).

Each of the above isomers is treated with trifluoroacetic acid to affordthe respective isomers of1-carboxymethyl-3-(1-ethoxycarbonyl-3-phenylpropyl)amino-7-phenyperhydroazepin-2-one as the trifluoroacetate salt.

Isomer A: NMR (CDCl₃, TMS): δ1.3 (t); δ1.5-2.6 (m); δ2.6-3.1 (m);δ3.6-3.9 (m); δ4.2 (q); δ4.0-4.8 (m); δ7.2 (s); δ8.9 (broad s).

Isomer B: NMR (DMSO-d₆, TMS): δ1.27 (t); δ1.6-3.1 (m); δ3.7-4.5 (m+q);δ4.7 (broad); δ5.1 (broad); δ7.2 (s); δ7.3 (s).

Each of the above isomers is treated with dilute sodium hyroxide, thenpurified by chromatography over acid ion exchange resin to afford thecorresponding isomers of1-carboxymethyl-3-(1-carboxy-3-phenylpropyl)amino-7-phenylperhydroazepin-2-one.

Isomer A: NMR (D₂ O+NaOD, dioxane=δ3.80): δ1.6-2.3 (broad m); δ2.55-2.9(m); δ3.25 (t); δ3.5-3.8 (m); δ4.6-5.1 (broad, obscured by H₂ O); δ7.3(s); δ7 35 (s).

Isomer B: NMR (D₂ O+NaOD, dioxane=δ3.80): 1.5-2.3 (broad m); δ2.5-2.9(m); δ3 25 (t); δ3.6 (broad s); δ3.7-4.2 (m); δ4.5-5.2 (m, obscured byH₂ O); δ7.25 (s); δ7.35 (s).

Similarly, treat the minor diastereomer of3-bromo-1-t-butoxycarbonylmethyl-7-phenylperhydroazepin-2-one asdescribed above and isolate a second pair of diacids which arediastereomeric racemates.

EXAMPLE 41 R² -Substituted Products of Formula I

By treatment with PCl₅ or PBr₅ in benzene or by following the proceduredecribed at the beginning of Example 40 but replacing the7-phenylperhydroazepin-2-one employed therein by perhydroazepin-2-onessubstituted in the 7 position by the groups listed in Table V, thecorresponding 7-substituted 3-bromo-perhydroazepin-2-ones could beobtained. By further treatment as described in Example 40 esters couldbe obtained of Formula I where R=OC₂ H₅, R₁ =CH₂ CH₂ φ, R₃ =R₅ =H, R₄=OH, and R₂ =the groups listed in Table V.

By additional treatment as described in Example 40, the correspondingdiacids could be obtained, where R=OH, R₁ =CH₂ CH₂ φ, R₃ =R₅ =H, R₄ =OH,and R₂ =the groups listed in Table V. The stereochemical consequences inthese cases parallel those described in the examples quoted.

                  TABLE V                                                         ______________________________________                                        7-Substituted Perhydroazepin-2-ones                                           ______________________________________                                                R.sub.2 =                                                                           --C.sub.2 H.sub.5                                                       n-C.sub.4 H.sub.9                                                             cyclohexyl                                                                    benzyl                                                                        (1-piperidino)methyl                                                           -p-tolyl                                                                      -p-anisyl                                                                     -p-chlorophenyl                                                              (2-pyridyl)                                                           ______________________________________                                         [All these compounds are described in the chemical literature            

EXAMPLE 42 R² -Aminoalkyl Substituted Products of Formula I

Perhydroazepin-2-ones substituted in the 7-position by 2-aminoethyl or4-aminobutyl groups, both of which are described in the chemicalliterature, could be converted to the corresponding phthalimidoderivative at their primary amine functionality by well-known methods,and the resulting compounds treated a described in Example 40 to afforddiesters of Formula I where R=OC₂ H₅, R₁ =CH₂ CH₂ φ, R₃ =R₅ =H, R₄=O-t-butyl, and R₂ represents ##STR9## where n=2 or 4, respectively.Careful hydrazinolysis would remove the phthalimide protecting group,affording the corresponding diesters, which could be treated withtrifluoracetic acid as described in Example 40 to afford the monoestersof Formula I where R=OC₂ H₅, R₁ =CH₂ CH₂ φ, R₃ =R₅ =H, R₄ =OH and R₂=(CH₂)_(u) NH₂ where u=2 or 4. Basic hydrolysis as described in theexample quoted would afford the corresponding diacids of Formula I whereR=R₄ =OH, R₁ =CH₂ CH₂ φ, R₃ =R₅ =H and R₂ =(CH₂)_(n) --NH₂ where n=2 or4.

The stereochemical consequences in these cases parallel those describedin the example quoted.

EXAMPLE 43

A typical tablet contains1-(1(S)-carboxyethyl)-3-(S)-[(1(S)-ethoxycarbonyl-3-phenylpropyl)amino]perhydroazepin-2-one(25 mg.), pregelatinized starch USP (82 mg.), microcrystalline cellulose(82 mg.) and magnesium stearate (1 mg.). In like manner, for example,1-(1(S)-carboxyethyl)-3-(S)-[(1(S)-carboxy-5-amino-1-pentyl)amino]perhydroazepin-2-one(20 mg.) may be formulated in place of1-(1(S)-carboxyethyl)-3-(S)-[(1(S)-ethoxycarbonyl-3-phenylpropyl)amino]perhydroazepin-2-one with the composition of pregelatinized starch,microcrystalline cellulose and magnesium stearate described above.

EXAMPLE 44 Compressed Tablet containing 5 mg. of active ingredient

    ______________________________________                                                             Per tablet, Mg.                                          ______________________________________                                        1(S)--Carboxyethyl-3-(S)--[(1(S)--                                                                   5                                                      ethoxycarbonyl-3-phenylpropyl)-                                               amino]-perhydroazepin-2-one                                                   Calcium phosphate dibasic                                                                            245                                                    Ethyl cellulose (as 5% solution in ethanol)                                                          5                                                      Unmixed granulation    255                                                    Add:                                                                          Starch, corn           14                                                     Magnesium stearate     1                                                                             270                                                    ______________________________________                                    

Directions: Mix the active ingredient above and calcium phosphate andreduce to a No. 60 mesh powder. Granulate with Ethocel in alcohol andpass the wet granulation through a No. 10 screen. Dry the granulation at110° F. for 12-18 hours. Dry grind to a No. 20 mesh. Incorporate the"adds" and compress into tablets each weighing 270 mg.

EXAMPLE 45 Dry filled capsule containing 5 mg. of active ingredient.

    ______________________________________                                                          Per capsule, mg.                                            ______________________________________                                        1-Carboxymethyl-3-(S)--[1(S)--                                                                    5                                                         ethoxy-carbonyl-3-phenyl-                                                     propyl]amino-7(S)--phenyl-                                                    perhydroazepin-2-one                                                          Lactose             273                                                       Magnesium stearate  2                                                         Mixed powders       280                                                       ______________________________________                                    

Mix the active ingredient above, lactose, and magnesium stearate andreduce to a No. 60 mesh powder. Encapsulate, filling 280 mg. in each No.2 capsule.

The above formulations can be employed to prepare compressed tablets orcapsules of other novel compounds of this invention hereinbeforedescribed.

While the above examples describe the preparation of certain compoundswhich are illustrative of the novel compounds of this invention andcertain specific dosage forms suitable for administering the novelcompounds, it is to be understood that the invention is not to belimited to the specific compounds described in the examples or by thespecific reaction conditions described for the preparation of thesecompounds or by the specific ingredients included in the pharmaceuticalpreparations, but is to be understood to embrace variations andmodifications thereof.

What is claimed is:
 1. The compound: ##STR10## and the lower alkyl andbenzyl esters thereof.
 2. The compound: ##STR11## and the lower alkyland benzyl esters thereof.
 3. The compound: ##STR12## and the loweralkyl and benzyl esters thereof.